Web and database programming tips

Web and database programming tips.

Contents:
1.	HTML and CSS tips
Mobile-friendly webpages
2.	Javascript tips
Setting the input focus onto a given form field Using Javascript to hide/show given text paragraphs Using Javascript to run a Perl CGI script
3.	PHP tips
4.	Perl tips
Internal server errors with Perl CGI scripts Generating device dependent webpages with Perl HTTP headers and CGI environment variables Extracting form data by parsing the HTTP request message Uploading files using Perl CGI
5.	MySQL tips
6.	Multimedia tips